Attachment-plug.



G. B. THOMAS.

ATTACHMENTPLUG.

APPLICATION FILED SEPT-9. 1916.

Patented. Dec. 4, 1912.

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GEORGE B. THOMAS, 013 BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE BRYANT ELEC- TRIO COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF CONNECTICUT.

ATTACHMENT-PLUG.

Application filed September 9, 1916.

T 0 all whom it may concern.-

Be it known that I, Gnonon B. THOMAS, a citizen of the United States of America, and residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented a certain new and useful Improvement in Attachment-Plugs, of which the following is a specification.

My invention relates to attachment plugs and particularly to plugs of the jack blade type, the object of my invention being to provide a plug in which the jack blades may be shifted to various relative positlons to cooperate with receptacles of different types in which the receiving contacts are variously arranged.

In the accompanying drawings,

Figure 1 is an inverted plan View of an attachment plug in which my invention is illustratively embodied;

Fig. 2 is a plan of a positioning disk of insulatin material which may be used to hold the ack blades in adjusted position;

Fig. 3 is a section on the line 33, Fig. 1*,

Figs. 1 and 5 are diagrams showing the jack blades of the plug' in different relative positions;

Fig. 6 is a side elevation of a modified form of jack blade, with the base plate in section;

, Fig. 7 is a plan of the base plate alone;

Fig. 8 is aside elevation of another modified form of jack blade with its base plate in section; and

Fig.9 is a plan of this base plate alone.

Attachment plugs having their plug ing jacks arranged substantially parallel or in tandem or (in a polarized plug) with their blades at right angles to each other, are well known devices on the market. In many cases the cooperating receptacles are constructed with contacts adapted to receive a plug of only one of the three types referred to, although certain receptables have been recently provided in which the recelvlng contacts are adapted to cooperate with two or even all threeof the types. So far as I am aware, however, no one has heretofore made a plug having its jack blades adjustable so that they may be arranged to cooperate with any of the three. types of receptacle contacts. This I have accomplished in the constructions shown herewith, and the improvement is one of particular importance to the manufacturer of electrical household Specification of Letters Patent.

Patented Dec. 4, 1917.

Serial No. 119,294.

appliances who sells his article with an attachment plug connection, but without knowledgeor even the possibility of knowledge-of the type of receptacle installed in the ultimate consumers house. To such a manufacturer, the possibility of supplying a plug which can be adapted to any one of these different types of receptacles, 1s a point of considerable commercial importance.

This adjustability of the plug contacts may be accomplished in various ways and I have shown only a few in the accom-' panying drawing.

Referring to Figs. 1 to 5 the present plug comprises an insulating body 10 pierced at 11 to admit the lead wires 12 and recessed to form an elliptical chamber 13 in which the strain relief knot in the wires may be seated. On opposite sides of the chamber 13 are depressed ledges 14 on which are mounted wire terminal plates 15 carrying binding screws 16. The jack blades 17 and 18 are pivotally secured to these terminal plates by base flanges 19 through which pass any suitable securing means such as diametrically opposite, tubular rivets 20, the heads of which lie in Wells 21 (Fig. 3) opening to the outer face of the plug and normally filled with insulating wax 22 or the like after the rivets have been inserted.

In the position shown in Figs. 1 and 3 the jack blades 17, 18, are arranged in tandem in a plane passing through the axis of the plug. While the frictional grip of the securing means 20 may be suflicient to hold the blades in this position under ordinary conditions, I prefer to provide a guard disk 23 (Fig. 2) which is slotted at 24, 25, to fit over the blades and hold them in this position. When assembled the disk is seated in shallow depression 26 and lies substantially flush with the inner face of the plug and within its peripheral margin.

If it is desired to convert the tandem arrangement of the blades into an arrangement wherein they stand at right angles to each other and thus into a polarized plug, it is only necessary to remove the guard disk 23 and turn the blade 18 on its pivot to the position shown in Fig. 1. While the blade 17 is now substantially at right angles thereto, it can be made more accurately so by pushing it slightly farther outward toward the periphery of the plug. While this results in moving the plane of the blade 17 slightly to one side of the axis of the plug, the arrangement is not objectionably eccentric. In this position of the blades the guard disk may be again adjusted, the blade 17 entering the slot 24, while the blade 18 enters the slot 27 lying at right angles to but communicating with slot 25. In order that the disk may be seated in its depression 26, the slot 27 is as Imnetrical with relation to the slot 25 an extends farther to one side of the other side. Su cient play between the sides of the slots and the blades is aiforded to accommodate the blades in the slots 24 and 27 as indicated.

Should it be desired to use the plug with a receptacle having only parallel receiving contacts, the guard disk 23 is again removed and the blade 17 swung to a position arallel to blade 18 the latter being swung Back slightly so that the plane passing through the middle of the blades is axial to the plug, as indicated in Fig. 5. The guard disk may be then readjusted, with blade 17 passing through slot 28 and blade 18 through slot 27, but at the end 29 of the latter opposite that occupied when in the position Fig. 4. In order to render the disk reversible, the slot 28 is extended at 30 so that it may be fitted over blade 18 in the polarized posltion (Fig. 4).

By locating the ledges on opposite sides of the short axis of the elliptical chamber 13 for the strain relief knot in the wires, and by arranging the terminal plates 15 toward the outer margins of the ledges, the blades 17 and 18 are kept suHiciently far away from the wires to prevent danger of accidental contact therewith, while at the same time the standard spacings for the blades in their different positions is retained.

Obviously other positions than those indicated can be secured, if desired. For instance, a polarized arrangement in which the blades lieat an obtuse angle to each other is shown in dotted lines at 31 (Fig. 2.). But this arrangement is little used and I have shown only such positions as have become standard on the market.

While there is little danger of defective contact between the terminal plates and the base flanges of the blades, I have shown in Fi 6 and 7, a different arrangement in which the terminal wires are directly connected to the blades. Thus in this construction the blade 32 is bent back on itself to form a wiring pocket 33 and tapped to re- -ceive'the binding screw 34 by which one of the wire ends is directly connected thereto. Since it would be impracticable to locate the uppertbend of the wiring pocket 33 within the area of the plu or to enlarge the plu to make this possibfia so that the guard dis c 23 could be used, I have shown a difierent lane of the latter than the method of holding the blades in adjusted position. To this end, the outer face of the terminal plate 35 is provided at suitable points with recesses or grooves 36, while the inner face of the base flange 37 of the.

jack blade has on its lower face a rib 38 which engages in one or the other of the grooves 36, depending upon the position of the blade. The blade is swung on its pivot 20, the rib 38 being sprung out of one roove 36 and into another, serving in eit er as sufficient means to hold the blade in proper position. More particularly is this so when it is realized that the adjustment once made is ordinarily not again changed durin use since the receptacles in a given dwe ing are ordinarily of uniform type.

A further modification for accomplishing the same result, is shown in Figs, 8 and 9. Here the base plate 39 is T-slotted as at 40, while the wire end of each jack blade 41 is split into a spring fork. The legs 42 of the latter have offset toes 43 which, when the fork is sprun through one or the other branch of the s 0t in the base plate, catch beneath the metal at the ends of the slots and hold the blade fast against accidentalv I withdrawal. To shift position of I blade it need only be disengaged from on branch of the slot and inserted in the other branch thereof.

The articular form of receptacle with which t e present lug cooperates is immaterial. The plug s own is of the type (30111,

'monly referred to as a cap, such as used with a separable attachment plug. But I do not limit the invention to this particular type nor to the details of construction shown,

which'may be variously modified and still accomplish what I claim as my invention.

I claim i 1. An attachment plug having relatively adjustable jack blades and a erforated member through which said bla es are inserted and by which they are held in adjust-- ed position.

2. An attachment plug having relatively adjustable jack blades and a T-slot perforated member through which said blades are .inserted and by Whlch they are held in ada diameter of the disk and on opposite sides of its axis, said slots accommodating the jack slots, lying substantiallyat right angles to blades in difi'erent positions of relative angular adjustment and serving to hold the blades in their adjusted positions.

5. An attachment plug having an insulating body recessed in one face, wire terminal plates accommodated on said recessed face,

jack blades pro'ecting from said lates beyond the face 0 said insulating b0 means for relative angular adjustment of said N blades and an insulating disk pierced to receive said blades in difierent relative angular positions, and lying against said recessed face in adjusted position. v

In testimony whereof I have signed my name to this specification, in the presence of 1-. two subscribing witnesses.

GEORGE B. THOS. Witnesses:

G. W. Goomunon, H. M. WIoHnn'r. 

